pc fails to boot without ram adjustment
I'm working on a computer. It was working fine previously, but booted to a black screen. When I adjusted the RAM (take a stick out and put it back in), the PC would boot fine again. This is not the first time this has happened, and it has also happened many times in the past.
I'm currently running MemTest86 to test all the ram, but I'm pretty confident the ram is good because it's fairly new.
Does anyone have any ideas of what the problem could be? I'll probably run a prime95 test on it to make sure everything is straight, but I don't really want to return this PC to its owner just to receive a phone call that it's not working again. I'd like to figure out exactly what the problem is instead of just continuing this workaround of displacing and place the ram.